1 /* 2 * Copyright (C) 1991, 1992 Linus Torvalds 3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs 4 * 5 * Pentium III FXSR, SSE support 6 * Gareth Hughes <gareth@valinux.com>, May 2000 7 */ 8 9 /* 10 * Handle hardware traps and faults. 11 */ 12 #include <linux/interrupt.h> 13 #include <linux/kallsyms.h> 14 #include <linux/spinlock.h> 15 #include <linux/kprobes.h> 16 #include <linux/uaccess.h> 17 #include <linux/utsname.h> 18 #include <linux/kdebug.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/ptrace.h> 22 #include <linux/string.h> 23 #include <linux/delay.h> 24 #include <linux/errno.h> 25 #include <linux/kexec.h> 26 #include <linux/sched.h> 27 #include <linux/timer.h> 28 #include <linux/init.h> 29 #include <linux/bug.h> 30 #include <linux/nmi.h> 31 #include <linux/mm.h> 32 #include <linux/smp.h> 33 #include <linux/io.h> 34 35 #ifdef CONFIG_EISA 36 #include <linux/ioport.h> 37 #include <linux/eisa.h> 38 #endif 39 40 #ifdef CONFIG_MCA 41 #include <linux/mca.h> 42 #endif 43 44 #if defined(CONFIG_EDAC) 45 #include <linux/edac.h> 46 #endif 47 48 #include <asm/kmemcheck.h> 49 #include <asm/stacktrace.h> 50 #include <asm/processor.h> 51 #include <asm/debugreg.h> 52 #include <asm/atomic.h> 53 #include <asm/system.h> 54 #include <asm/traps.h> 55 #include <asm/desc.h> 56 #include <asm/i387.h> 57 #include <asm/mce.h> 58 59 #include <asm/mach_traps.h> 60 61 #ifdef CONFIG_X86_64 62 #include <asm/pgalloc.h> 63 #include <asm/proto.h> 64 #else 65 #include <asm/processor-flags.h> 66 #include <asm/setup.h> 67 #include <asm/traps.h> 68 69 asmlinkage int system_call(void); 70 71 /* Do we ignore FPU interrupts ? */ 72 char ignore_fpu_irq; 73 74 /* 75 * The IDT has to be page-aligned to simplify the Pentium 76 * F0 0F bug workaround.. We have a special link segment 77 * for this. 78 */ 79 gate_desc idt_table[256] 80 __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, }; 81 #endif 82 83 DECLARE_BITMAP(used_vectors, NR_VECTORS); 84 EXPORT_SYMBOL_GPL(used_vectors); 85 86 static int ignore_nmis; 87 88 static inline void conditional_sti(struct pt_regs *regs) 89 { 90 if (regs->flags & X86_EFLAGS_IF) 91 local_irq_enable(); 92 } 93 94 static inline void preempt_conditional_sti(struct pt_regs *regs) 95 { 96 inc_preempt_count(); 97 if (regs->flags & X86_EFLAGS_IF) 98 local_irq_enable(); 99 } 100 101 static inline void conditional_cli(struct pt_regs *regs) 102 { 103 if (regs->flags & X86_EFLAGS_IF) 104 local_irq_disable(); 105 } 106 107 static inline void preempt_conditional_cli(struct pt_regs *regs) 108 { 109 if (regs->flags & X86_EFLAGS_IF) 110 local_irq_disable(); 111 dec_preempt_count(); 112 } 113 114 #ifdef CONFIG_X86_32 115 static inline void 116 die_if_kernel(const char *str, struct pt_regs *regs, long err) 117 { 118 if (!user_mode_vm(regs)) 119 die(str, regs, err); 120 } 121 #endif 122 123 static void __kprobes 124 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, 125 long error_code, siginfo_t *info) 126 { 127 struct task_struct *tsk = current; 128 129 #ifdef CONFIG_X86_32 130 if (regs->flags & X86_VM_MASK) { 131 /* 132 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. 133 * On nmi (interrupt 2), do_trap should not be called. 134 */ 135 if (trapnr < 6) 136 goto vm86_trap; 137 goto trap_signal; 138 } 139 #endif 140 141 if (!user_mode(regs)) 142 goto kernel_trap; 143 144 #ifdef CONFIG_X86_32 145 trap_signal: 146 #endif 147 /* 148 * We want error_code and trap_no set for userspace faults and 149 * kernelspace faults which result in die(), but not 150 * kernelspace faults which are fixed up. die() gives the 151 * process no chance to handle the signal and notice the 152 * kernel fault information, so that won't result in polluting 153 * the information about previously queued, but not yet 154 * delivered, faults. See also do_general_protection below. 155 */ 156 tsk->thread.error_code = error_code; 157 tsk->thread.trap_no = trapnr; 158 159 #ifdef CONFIG_X86_64 160 if (show_unhandled_signals && unhandled_signal(tsk, signr) && 161 printk_ratelimit()) { 162 printk(KERN_INFO 163 "%s[%d] trap %s ip:%lx sp:%lx error:%lx", 164 tsk->comm, tsk->pid, str, 165 regs->ip, regs->sp, error_code); 166 print_vma_addr(" in ", regs->ip); 167 printk("\n"); 168 } 169 #endif 170 171 if (info) 172 force_sig_info(signr, info, tsk); 173 else 174 force_sig(signr, tsk); 175 return; 176 177 kernel_trap: 178 if (!fixup_exception(regs)) { 179 tsk->thread.error_code = error_code; 180 tsk->thread.trap_no = trapnr; 181 die(str, regs, error_code); 182 } 183 return; 184 185 #ifdef CONFIG_X86_32 186 vm86_trap: 187 if (handle_vm86_trap((struct kernel_vm86_regs *) regs, 188 error_code, trapnr)) 189 goto trap_signal; 190 return; 191 #endif 192 } 193 194 #define DO_ERROR(trapnr, signr, str, name) \ 195 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 196 { \ 197 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 198 == NOTIFY_STOP) \ 199 return; \ 200 conditional_sti(regs); \ 201 do_trap(trapnr, signr, str, regs, error_code, NULL); \ 202 } 203 204 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ 205 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 206 { \ 207 siginfo_t info; \ 208 info.si_signo = signr; \ 209 info.si_errno = 0; \ 210 info.si_code = sicode; \ 211 info.si_addr = (void __user *)siaddr; \ 212 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 213 == NOTIFY_STOP) \ 214 return; \ 215 conditional_sti(regs); \ 216 do_trap(trapnr, signr, str, regs, error_code, &info); \ 217 } 218 219 DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip) 220 DO_ERROR(4, SIGSEGV, "overflow", overflow) 221 DO_ERROR(5, SIGSEGV, "bounds", bounds) 222 DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip) 223 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) 224 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) 225 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) 226 #ifdef CONFIG_X86_32 227 DO_ERROR(12, SIGBUS, "stack segment", stack_segment) 228 #endif 229 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) 230 231 #ifdef CONFIG_X86_64 232 /* Runs on IST stack */ 233 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) 234 { 235 if (notify_die(DIE_TRAP, "stack segment", regs, error_code, 236 12, SIGBUS) == NOTIFY_STOP) 237 return; 238 preempt_conditional_sti(regs); 239 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); 240 preempt_conditional_cli(regs); 241 } 242 243 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) 244 { 245 static const char str[] = "double fault"; 246 struct task_struct *tsk = current; 247 248 /* Return not checked because double check cannot be ignored */ 249 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); 250 251 tsk->thread.error_code = error_code; 252 tsk->thread.trap_no = 8; 253 254 /* 255 * This is always a kernel trap and never fixable (and thus must 256 * never return). 257 */ 258 for (;;) 259 die(str, regs, error_code); 260 } 261 #endif 262 263 dotraplinkage void __kprobes 264 do_general_protection(struct pt_regs *regs, long error_code) 265 { 266 struct task_struct *tsk; 267 268 conditional_sti(regs); 269 270 #ifdef CONFIG_X86_32 271 if (regs->flags & X86_VM_MASK) 272 goto gp_in_vm86; 273 #endif 274 275 tsk = current; 276 if (!user_mode(regs)) 277 goto gp_in_kernel; 278 279 tsk->thread.error_code = error_code; 280 tsk->thread.trap_no = 13; 281 282 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && 283 printk_ratelimit()) { 284 printk(KERN_INFO 285 "%s[%d] general protection ip:%lx sp:%lx error:%lx", 286 tsk->comm, task_pid_nr(tsk), 287 regs->ip, regs->sp, error_code); 288 print_vma_addr(" in ", regs->ip); 289 printk("\n"); 290 } 291 292 force_sig(SIGSEGV, tsk); 293 return; 294 295 #ifdef CONFIG_X86_32 296 gp_in_vm86: 297 local_irq_enable(); 298 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); 299 return; 300 #endif 301 302 gp_in_kernel: 303 if (fixup_exception(regs)) 304 return; 305 306 tsk->thread.error_code = error_code; 307 tsk->thread.trap_no = 13; 308 if (notify_die(DIE_GPF, "general protection fault", regs, 309 error_code, 13, SIGSEGV) == NOTIFY_STOP) 310 return; 311 die("general protection fault", regs, error_code); 312 } 313 314 static notrace __kprobes void 315 mem_parity_error(unsigned char reason, struct pt_regs *regs) 316 { 317 printk(KERN_EMERG 318 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", 319 reason, smp_processor_id()); 320 321 printk(KERN_EMERG 322 "You have some hardware problem, likely on the PCI bus.\n"); 323 324 #if defined(CONFIG_EDAC) 325 if (edac_handler_set()) { 326 edac_atomic_assert_error(); 327 return; 328 } 329 #endif 330 331 if (panic_on_unrecovered_nmi) 332 panic("NMI: Not continuing"); 333 334 printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); 335 336 /* Clear and disable the memory parity error line. */ 337 reason = (reason & 0xf) | 4; 338 outb(reason, 0x61); 339 } 340 341 static notrace __kprobes void 342 io_check_error(unsigned char reason, struct pt_regs *regs) 343 { 344 unsigned long i; 345 346 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n"); 347 show_registers(regs); 348 349 if (panic_on_io_nmi) 350 panic("NMI IOCK error: Not continuing"); 351 352 /* Re-enable the IOCK line, wait for a few seconds */ 353 reason = (reason & 0xf) | 8; 354 outb(reason, 0x61); 355 356 i = 2000; 357 while (--i) 358 udelay(1000); 359 360 reason &= ~8; 361 outb(reason, 0x61); 362 } 363 364 static notrace __kprobes void 365 unknown_nmi_error(unsigned char reason, struct pt_regs *regs) 366 { 367 if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == 368 NOTIFY_STOP) 369 return; 370 #ifdef CONFIG_MCA 371 /* 372 * Might actually be able to figure out what the guilty party 373 * is: 374 */ 375 if (MCA_bus) { 376 mca_handle_nmi(); 377 return; 378 } 379 #endif 380 printk(KERN_EMERG 381 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", 382 reason, smp_processor_id()); 383 384 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); 385 if (panic_on_unrecovered_nmi) 386 panic("NMI: Not continuing"); 387 388 printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); 389 } 390 391 static notrace __kprobes void default_do_nmi(struct pt_regs *regs) 392 { 393 unsigned char reason = 0; 394 int cpu; 395 396 cpu = smp_processor_id(); 397 398 /* Only the BSP gets external NMIs from the system. */ 399 if (!cpu) 400 reason = get_nmi_reason(); 401 402 if (!(reason & 0xc0)) { 403 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) 404 == NOTIFY_STOP) 405 return; 406 #ifdef CONFIG_X86_LOCAL_APIC 407 /* 408 * Ok, so this is none of the documented NMI sources, 409 * so it must be the NMI watchdog. 410 */ 411 if (nmi_watchdog_tick(regs, reason)) 412 return; 413 if (!do_nmi_callback(regs, cpu)) 414 unknown_nmi_error(reason, regs); 415 #else 416 unknown_nmi_error(reason, regs); 417 #endif 418 419 return; 420 } 421 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) 422 return; 423 424 /* AK: following checks seem to be broken on modern chipsets. FIXME */ 425 if (reason & 0x80) 426 mem_parity_error(reason, regs); 427 if (reason & 0x40) 428 io_check_error(reason, regs); 429 #ifdef CONFIG_X86_32 430 /* 431 * Reassert NMI in case it became active meanwhile 432 * as it's edge-triggered: 433 */ 434 reassert_nmi(); 435 #endif 436 } 437 438 dotraplinkage notrace __kprobes void 439 do_nmi(struct pt_regs *regs, long error_code) 440 { 441 nmi_enter(); 442 443 inc_irq_stat(__nmi_count); 444 445 if (!ignore_nmis) 446 default_do_nmi(regs); 447 448 nmi_exit(); 449 } 450 451 void stop_nmi(void) 452 { 453 acpi_nmi_disable(); 454 ignore_nmis++; 455 } 456 457 void restart_nmi(void) 458 { 459 ignore_nmis--; 460 acpi_nmi_enable(); 461 } 462 463 /* May run on IST stack. */ 464 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) 465 { 466 #ifdef CONFIG_KPROBES 467 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) 468 == NOTIFY_STOP) 469 return; 470 #else 471 if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP) 472 == NOTIFY_STOP) 473 return; 474 #endif 475 476 preempt_conditional_sti(regs); 477 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); 478 preempt_conditional_cli(regs); 479 } 480 481 #ifdef CONFIG_X86_64 482 /* 483 * Help handler running on IST stack to switch back to user stack 484 * for scheduling or signal handling. The actual stack switch is done in 485 * entry.S 486 */ 487 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) 488 { 489 struct pt_regs *regs = eregs; 490 /* Did already sync */ 491 if (eregs == (struct pt_regs *)eregs->sp) 492 ; 493 /* Exception from user space */ 494 else if (user_mode(eregs)) 495 regs = task_pt_regs(current); 496 /* 497 * Exception from kernel and interrupts are enabled. Move to 498 * kernel process stack. 499 */ 500 else if (eregs->flags & X86_EFLAGS_IF) 501 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); 502 if (eregs != regs) 503 *regs = *eregs; 504 return regs; 505 } 506 #endif 507 508 /* 509 * Our handling of the processor debug registers is non-trivial. 510 * We do not clear them on entry and exit from the kernel. Therefore 511 * it is possible to get a watchpoint trap here from inside the kernel. 512 * However, the code in ./ptrace.c has ensured that the user can 513 * only set watchpoints on userspace addresses. Therefore the in-kernel 514 * watchpoint trap can only occur in code which is reading/writing 515 * from user space. Such code must not hold kernel locks (since it 516 * can equally take a page fault), therefore it is safe to call 517 * force_sig_info even though that claims and releases locks. 518 * 519 * Code in ./signal.c ensures that the debug control register 520 * is restored before we deliver any signal, and therefore that 521 * user code runs with the correct debug control register even though 522 * we clear it here. 523 * 524 * Being careful here means that we don't have to be as careful in a 525 * lot of more complicated places (task switching can be a bit lazy 526 * about restoring all the debug state, and ptrace doesn't have to 527 * find every occurrence of the TF bit that could be saved away even 528 * by user code) 529 * 530 * May run on IST stack. 531 */ 532 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) 533 { 534 struct task_struct *tsk = current; 535 unsigned long condition; 536 int si_code; 537 538 get_debugreg(condition, 6); 539 540 /* Catch kmemcheck conditions first of all! */ 541 if (condition & DR_STEP && kmemcheck_trap(regs)) 542 return; 543 544 /* 545 * The processor cleared BTF, so don't mark that we need it set. 546 */ 547 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR); 548 tsk->thread.debugctlmsr = 0; 549 550 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, 551 SIGTRAP) == NOTIFY_STOP) 552 return; 553 554 /* It's safe to allow irq's after DR6 has been saved */ 555 preempt_conditional_sti(regs); 556 557 /* Mask out spurious debug traps due to lazy DR7 setting */ 558 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { 559 if (!tsk->thread.debugreg7) 560 goto clear_dr7; 561 } 562 563 #ifdef CONFIG_X86_32 564 if (regs->flags & X86_VM_MASK) 565 goto debug_vm86; 566 #endif 567 568 /* Save debug status register where ptrace can see it */ 569 tsk->thread.debugreg6 = condition; 570 571 /* 572 * Single-stepping through TF: make sure we ignore any events in 573 * kernel space (but re-enable TF when returning to user mode). 574 */ 575 if (condition & DR_STEP) { 576 if (!user_mode(regs)) 577 goto clear_TF_reenable; 578 } 579 580 si_code = get_si_code(condition); 581 /* Ok, finally something we can handle */ 582 send_sigtrap(tsk, regs, error_code, si_code); 583 584 /* 585 * Disable additional traps. They'll be re-enabled when 586 * the signal is delivered. 587 */ 588 clear_dr7: 589 set_debugreg(0, 7); 590 preempt_conditional_cli(regs); 591 return; 592 593 #ifdef CONFIG_X86_32 594 debug_vm86: 595 /* reenable preemption: handle_vm86_trap() might sleep */ 596 dec_preempt_count(); 597 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1); 598 conditional_cli(regs); 599 return; 600 #endif 601 602 clear_TF_reenable: 603 set_tsk_thread_flag(tsk, TIF_SINGLESTEP); 604 regs->flags &= ~X86_EFLAGS_TF; 605 preempt_conditional_cli(regs); 606 return; 607 } 608 609 #ifdef CONFIG_X86_64 610 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) 611 { 612 if (fixup_exception(regs)) 613 return 1; 614 615 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); 616 /* Illegal floating point operation in the kernel */ 617 current->thread.trap_no = trapnr; 618 die(str, regs, 0); 619 return 0; 620 } 621 #endif 622 623 /* 624 * Note that we play around with the 'TS' bit in an attempt to get 625 * the correct behaviour even in the presence of the asynchronous 626 * IRQ13 behaviour 627 */ 628 void math_error(void __user *ip) 629 { 630 struct task_struct *task; 631 siginfo_t info; 632 unsigned short cwd, swd, err; 633 634 /* 635 * Save the info for the exception handler and clear the error. 636 */ 637 task = current; 638 save_init_fpu(task); 639 task->thread.trap_no = 16; 640 task->thread.error_code = 0; 641 info.si_signo = SIGFPE; 642 info.si_errno = 0; 643 info.si_addr = ip; 644 /* 645 * (~cwd & swd) will mask out exceptions that are not set to unmasked 646 * status. 0x3f is the exception bits in these regs, 0x200 is the 647 * C1 reg you need in case of a stack fault, 0x040 is the stack 648 * fault bit. We should only be taking one exception at a time, 649 * so if this combination doesn't produce any single exception, 650 * then we have a bad program that isn't synchronizing its FPU usage 651 * and it will suffer the consequences since we won't be able to 652 * fully reproduce the context of the exception 653 */ 654 cwd = get_fpu_cwd(task); 655 swd = get_fpu_swd(task); 656 657 err = swd & ~cwd; 658 659 if (err & 0x001) { /* Invalid op */ 660 /* 661 * swd & 0x240 == 0x040: Stack Underflow 662 * swd & 0x240 == 0x240: Stack Overflow 663 * User must clear the SF bit (0x40) if set 664 */ 665 info.si_code = FPE_FLTINV; 666 } else if (err & 0x004) { /* Divide by Zero */ 667 info.si_code = FPE_FLTDIV; 668 } else if (err & 0x008) { /* Overflow */ 669 info.si_code = FPE_FLTOVF; 670 } else if (err & 0x012) { /* Denormal, Underflow */ 671 info.si_code = FPE_FLTUND; 672 } else if (err & 0x020) { /* Precision */ 673 info.si_code = FPE_FLTRES; 674 } else { 675 /* 676 * If we're using IRQ 13, or supposedly even some trap 16 677 * implementations, it's possible we get a spurious trap... 678 */ 679 return; /* Spurious trap, no error */ 680 } 681 force_sig_info(SIGFPE, &info, task); 682 } 683 684 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) 685 { 686 conditional_sti(regs); 687 688 #ifdef CONFIG_X86_32 689 ignore_fpu_irq = 1; 690 #else 691 if (!user_mode(regs) && 692 kernel_math_error(regs, "kernel x87 math error", 16)) 693 return; 694 #endif 695 696 math_error((void __user *)regs->ip); 697 } 698 699 static void simd_math_error(void __user *ip) 700 { 701 struct task_struct *task; 702 siginfo_t info; 703 unsigned short mxcsr; 704 705 /* 706 * Save the info for the exception handler and clear the error. 707 */ 708 task = current; 709 save_init_fpu(task); 710 task->thread.trap_no = 19; 711 task->thread.error_code = 0; 712 info.si_signo = SIGFPE; 713 info.si_errno = 0; 714 info.si_code = __SI_FAULT; 715 info.si_addr = ip; 716 /* 717 * The SIMD FPU exceptions are handled a little differently, as there 718 * is only a single status/control register. Thus, to determine which 719 * unmasked exception was caught we must mask the exception mask bits 720 * at 0x1f80, and then use these to mask the exception bits at 0x3f. 721 */ 722 mxcsr = get_fpu_mxcsr(task); 723 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { 724 case 0x000: 725 default: 726 break; 727 case 0x001: /* Invalid Op */ 728 info.si_code = FPE_FLTINV; 729 break; 730 case 0x002: /* Denormalize */ 731 case 0x010: /* Underflow */ 732 info.si_code = FPE_FLTUND; 733 break; 734 case 0x004: /* Zero Divide */ 735 info.si_code = FPE_FLTDIV; 736 break; 737 case 0x008: /* Overflow */ 738 info.si_code = FPE_FLTOVF; 739 break; 740 case 0x020: /* Precision */ 741 info.si_code = FPE_FLTRES; 742 break; 743 } 744 force_sig_info(SIGFPE, &info, task); 745 } 746 747 dotraplinkage void 748 do_simd_coprocessor_error(struct pt_regs *regs, long error_code) 749 { 750 conditional_sti(regs); 751 752 #ifdef CONFIG_X86_32 753 if (cpu_has_xmm) { 754 /* Handle SIMD FPU exceptions on PIII+ processors. */ 755 ignore_fpu_irq = 1; 756 simd_math_error((void __user *)regs->ip); 757 return; 758 } 759 /* 760 * Handle strange cache flush from user space exception 761 * in all other cases. This is undocumented behaviour. 762 */ 763 if (regs->flags & X86_VM_MASK) { 764 handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code); 765 return; 766 } 767 current->thread.trap_no = 19; 768 current->thread.error_code = error_code; 769 die_if_kernel("cache flush denied", regs, error_code); 770 force_sig(SIGSEGV, current); 771 #else 772 if (!user_mode(regs) && 773 kernel_math_error(regs, "kernel simd math error", 19)) 774 return; 775 simd_math_error((void __user *)regs->ip); 776 #endif 777 } 778 779 dotraplinkage void 780 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) 781 { 782 conditional_sti(regs); 783 #if 0 784 /* No need to warn about this any longer. */ 785 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); 786 #endif 787 } 788 789 #ifdef CONFIG_X86_32 790 unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp) 791 { 792 struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id()); 793 unsigned long base = (kesp - uesp) & -THREAD_SIZE; 794 unsigned long new_kesp = kesp - base; 795 unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT; 796 __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS]; 797 798 /* Set up base for espfix segment */ 799 desc &= 0x00f0ff0000000000ULL; 800 desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) | 801 ((((__u64)base) << 32) & 0xff00000000000000ULL) | 802 ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) | 803 (lim_pages & 0xffff); 804 *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc; 805 806 return new_kesp; 807 } 808 #endif 809 810 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) 811 { 812 } 813 814 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) 815 { 816 } 817 818 /* 819 * 'math_state_restore()' saves the current math information in the 820 * old math state array, and gets the new ones from the current task 821 * 822 * Careful.. There are problems with IBM-designed IRQ13 behaviour. 823 * Don't touch unless you *really* know how it works. 824 * 825 * Must be called with kernel preemption disabled (in this case, 826 * local interrupts are disabled at the call-site in entry.S). 827 */ 828 asmlinkage void math_state_restore(void) 829 { 830 struct thread_info *thread = current_thread_info(); 831 struct task_struct *tsk = thread->task; 832 833 if (!tsk_used_math(tsk)) { 834 local_irq_enable(); 835 /* 836 * does a slab alloc which can sleep 837 */ 838 if (init_fpu(tsk)) { 839 /* 840 * ran out of memory! 841 */ 842 do_group_exit(SIGKILL); 843 return; 844 } 845 local_irq_disable(); 846 } 847 848 clts(); /* Allow maths ops (or we recurse) */ 849 /* 850 * Paranoid restore. send a SIGSEGV if we fail to restore the state. 851 */ 852 if (unlikely(restore_fpu_checking(tsk))) { 853 stts(); 854 force_sig(SIGSEGV, tsk); 855 return; 856 } 857 858 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ 859 tsk->fpu_counter++; 860 } 861 EXPORT_SYMBOL_GPL(math_state_restore); 862 863 #ifndef CONFIG_MATH_EMULATION 864 void math_emulate(struct math_emu_info *info) 865 { 866 printk(KERN_EMERG 867 "math-emulation not enabled and no coprocessor found.\n"); 868 printk(KERN_EMERG "killing %s.\n", current->comm); 869 force_sig(SIGFPE, current); 870 schedule(); 871 } 872 #endif /* CONFIG_MATH_EMULATION */ 873 874 dotraplinkage void __kprobes 875 do_device_not_available(struct pt_regs *regs, long error_code) 876 { 877 #ifdef CONFIG_X86_32 878 if (read_cr0() & X86_CR0_EM) { 879 struct math_emu_info info = { }; 880 881 conditional_sti(regs); 882 883 info.regs = regs; 884 math_emulate(&info); 885 } else { 886 math_state_restore(); /* interrupts still off */ 887 conditional_sti(regs); 888 } 889 #else 890 math_state_restore(); 891 #endif 892 } 893 894 #ifdef CONFIG_X86_32 895 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) 896 { 897 siginfo_t info; 898 local_irq_enable(); 899 900 info.si_signo = SIGILL; 901 info.si_errno = 0; 902 info.si_code = ILL_BADSTK; 903 info.si_addr = NULL; 904 if (notify_die(DIE_TRAP, "iret exception", 905 regs, error_code, 32, SIGILL) == NOTIFY_STOP) 906 return; 907 do_trap(32, SIGILL, "iret exception", regs, error_code, &info); 908 } 909 #endif 910 911 void __init trap_init(void) 912 { 913 int i; 914 915 #ifdef CONFIG_EISA 916 void __iomem *p = early_ioremap(0x0FFFD9, 4); 917 918 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) 919 EISA_bus = 1; 920 early_iounmap(p, 4); 921 #endif 922 923 set_intr_gate(0, ÷_error); 924 set_intr_gate_ist(1, &debug, DEBUG_STACK); 925 set_intr_gate_ist(2, &nmi, NMI_STACK); 926 /* int3 can be called from all */ 927 set_system_intr_gate_ist(3, &int3, DEBUG_STACK); 928 /* int4 can be called from all */ 929 set_system_intr_gate(4, &overflow); 930 set_intr_gate(5, &bounds); 931 set_intr_gate(6, &invalid_op); 932 set_intr_gate(7, &device_not_available); 933 #ifdef CONFIG_X86_32 934 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS); 935 #else 936 set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK); 937 #endif 938 set_intr_gate(9, &coprocessor_segment_overrun); 939 set_intr_gate(10, &invalid_TSS); 940 set_intr_gate(11, &segment_not_present); 941 set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK); 942 set_intr_gate(13, &general_protection); 943 set_intr_gate(14, &page_fault); 944 set_intr_gate(15, &spurious_interrupt_bug); 945 set_intr_gate(16, &coprocessor_error); 946 set_intr_gate(17, &alignment_check); 947 #ifdef CONFIG_X86_MCE 948 set_intr_gate_ist(18, &machine_check, MCE_STACK); 949 #endif 950 set_intr_gate(19, &simd_coprocessor_error); 951 952 /* Reserve all the builtin and the syscall vector: */ 953 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) 954 set_bit(i, used_vectors); 955 956 #ifdef CONFIG_IA32_EMULATION 957 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); 958 set_bit(IA32_SYSCALL_VECTOR, used_vectors); 959 #endif 960 961 #ifdef CONFIG_X86_32 962 if (cpu_has_fxsr) { 963 printk(KERN_INFO "Enabling fast FPU save and restore... "); 964 set_in_cr4(X86_CR4_OSFXSR); 965 printk("done.\n"); 966 } 967 if (cpu_has_xmm) { 968 printk(KERN_INFO 969 "Enabling unmasked SIMD FPU exception support... "); 970 set_in_cr4(X86_CR4_OSXMMEXCPT); 971 printk("done.\n"); 972 } 973 974 set_system_trap_gate(SYSCALL_VECTOR, &system_call); 975 set_bit(SYSCALL_VECTOR, used_vectors); 976 #endif 977 978 /* 979 * Should be a barrier for any external CPU state: 980 */ 981 cpu_init(); 982 983 #ifdef CONFIG_X86_32 984 x86_quirk_trap_init(); 985 #endif 986 } 987